GL looks at route-specific container stowage

Tuesday, January 22, 2013

The classification society Germanischer Lloyd said it is developing guidelines for route-specific container stowage, which will be introduced early this year.
"In times when the market is especially tight, added flexibility in container stowage can help operators stay competitive and run vessels more economically. Throughout the maritime industry there is an increasing recognition that not using an 'off-the-rack' solution, whether in ship design and operation or the management of a fleet, can bring clear benefits to the market," GL said in its Navigator newsletter.
"In container stowage and loading it is no different – being able to tailor a loading plan to an individual vessel and its particular route will make it possible to optimize the loading flexibility of every vessel in a fleet. With overcapacity, high fuel prices and the cascade effect of extremely large vessels entering the market, ensuring that each individual vessel maximizes its capacity while maintaining its loading flexibility, is essential. That is why GL has devised a few methods to show that these factors need not contradict each other."
GL noted new ships can increase capacity by raising the bridge deck or moving the bridge forward. But it said "existing vessels also often have the potential to increase their deck capacity while observing the applicable international regulations without the need for a costly redesign or refit."
The international standard is to design a vessel fit for 20 years of operation in the North Atlantic and that the same requirements are commonly applied to the design of lashing systems, said GL. But it noted many ships will not operate only in the North Atlantic and while they may encounter areas of severe sea conditions, they may also sail in relatively calm regions for a considerable amount of their service life.
Applying long-term statistics, GL said it's possible to consider realistic routes for the determination of loads on deck containers and their lashing systems.
"The wave load analysis of a typical Asia-Europe route for a megaboxer has revealed the potential for limitless service when considering the rule load: While retaining the same safety levels, it will not only be possible to integrate an extra tier, but a more flexible weight distribution and real container weights can be applied. This flexibility enables operators to increase the number of loadable containers they are able to carry and reduce the number of empty containers transported," the classification society said.
"GL is currently working on the development of class notations for route-dependent container stowage. When applying this scheme, instead of having different stowage plans on board, lashing software will assist the cargo planner, as well as the crew, in providing safe stowage and lashing while being flexible enough to take advantage of opportunities whenever they might arise," it added. - Chris Dupin